The present invention relates generally to industrial robot systems, and more particularly relates to industrial robot systems used for fabricating components for image forming systems.
Many industrial robot systems utilized to perform precision assembly of electronic devices such as, electronic devices containing multiple Light Emitting Diodes (LED) for use in image forming systems, such as scanners and printers, are capable of achieving a workpiece placement accuracy of between 25 microns and 50 microns. Nonetheless, in a high volume manufacturing setting, the component placement accuracy of the industrial robot deteriorates during use. For example, the stresses associated with repetitive movements cause thermal warming and cooling which significantly impacts the systems placement accuracy. As a result, workpiece placement accuracy of greater than 15 microns is difficult to achieve in a high volume manufacturing environment.
The conventional method and apparatus for achieving greater workpiece placement accuracy with an industrial robot system has been to use two fixed cameras located over the workpiece placement location. The two fixed cameras identify a desired workpiece placement location by imaging the desired placement location and the industrial robot to provide feedback correction data. The benefits of this technique include the negation of inaccuracies caused by thermal cycling, e.g., warming and cooling, and the correction of inherent industrial robot movement inaccuracies.
The use of two fixed cameras located over a workpiece placement location does not provide sufficient accuracy when placing multiple workpieces in a densely populated electronic device. Specifically, the two fixed cameras cannot accurately view multiple chips over the length or width of the populated substrate, and therefore, lacks the ability to align multiple workpieces relative to one another. As such, high workpiece density electronic devices requiring workpiece placement accuracy better than 15 to 25 microns is burdensome and oftentimes requires manual labor intervention to ensure accurate workpiece placement.
Because a single point pick up tool, such as a vacuum pen, has a small profile relative to the workpiece, the use of a single point tool facilitates the imaging of the retrieved workpiece. Nonetheless, conventional workpieces lack sufficient rigidity to be picked and placed using the tool.
The present invention addresses the above described problems of conventional assembly tooling utilized in manufacture of electronic devices requiring highly accurate component placement. In particular, the present invention provides a tooling adapter for use with an industrial robot system that facilitates high component placement accuracy.
The present invention is directed to a system for manipulating a workpiece in an industrial robot system having a manipulator device for manipulating the workpiece, a tooling adapter coupled to the manipulator device for manipulating the workpiece when disposed in selected engagement therewith, and an image referencing system for acquiring image data corresponding to the workpiece.
According to one aspect, the system can also include an air bearing assembly coupled to the manipulator device and the image referencing system, where the manipulator device and/or the image referencing system can move along the air bearing assembly. The system can also include a base coupled to one or more support members that support the air bearing assembly.
According to another aspect, the image referencing system comprises an image acquisition element, and optionally one or more of an optical lens coupled to the image acquisition element, a prism optically coupled to the image acquisition element, and a quill disposed between the optical lens and the prism.
According to another aspect, the tooling adapter can include a viewing window positioned relative to the image referencing system for allowing the image referencing system to acquire the image data corresponding to the workpiece without interference from the manipulator device. The tooling adapter can also include a vacuum assembly for applying a force to a workpiece for manipulating the workpiece.
According to another aspect, the tooling adapter comprises a housing have a platen top surface adapted for coupling to the manipulator device, one or more walls coupled to the platen, and a bottom portion coupled to the wall. The bottom portion comprises a vacuum assembly having a plurality of ports for applying a force to the workpiece when disposed in contact therewith.
According to another aspect, the bottom portion of the tooling adapter further include a window for allowing the image referencing system to acquire the image data of the workpiece without interference from the manipulator device.
The present invention also provides for a method for manipulating a workpiece comprising the steps of manipulating the workpiece with a manipulator device, coupling a tooling adapter to the manipulator device, and acquiring image data corresponding to the workpiece without interference from the manipulator device.